From: Wolfram Sang wsa+renesas@sang-engineering.com
[ Upstream commit 2e586f8a5b0ed4a525014a692923ac96f6647816 ]
If we reset because of an error, we need to preserve values for the clock frequency. Otherwise, glitches may be seen on the bus.
To achieve that, we introduce a 'preserve' parameter to the reset function and the IP core specific reset callbacks to handle everything accordingly.
Reported-by: Yoshihiro Shimoda yoshihiro.shimoda.uh@renesas.com Signed-off-by: Wolfram Sang wsa+renesas@sang-engineering.com Tested-by: Yoshihiro Shimoda yoshihiro.shimoda.uh@renesas.com Link: https://lore.kernel.org/r/20220625131722.1397-1-wsa@kernel.org Signed-off-by: Ulf Hansson ulf.hansson@linaro.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/mmc/host/renesas_sdhi_core.c | 29 ++++++++++++++-------------- drivers/mmc/host/tmio_mmc.c | 2 +- drivers/mmc/host/tmio_mmc.h | 6 +++++- drivers/mmc/host/tmio_mmc_core.c | 28 +++++++++++++++++++++------ 4 files changed, 42 insertions(+), 23 deletions(-)
diff --git a/drivers/mmc/host/renesas_sdhi_core.c b/drivers/mmc/host/renesas_sdhi_core.c index 0d258b6e1a43..55f7b27c3de7 100644 --- a/drivers/mmc/host/renesas_sdhi_core.c +++ b/drivers/mmc/host/renesas_sdhi_core.c @@ -49,9 +49,6 @@ #define HOST_MODE_GEN3_32BIT (HOST_MODE_GEN3_WMODE | HOST_MODE_GEN3_BUSWIDTH) #define HOST_MODE_GEN3_64BIT 0
-#define CTL_SDIF_MODE 0xe6 -#define SDIF_MODE_HS400 BIT(0) - #define SDHI_VER_GEN2_SDR50 0x490c #define SDHI_VER_RZ_A1 0x820b /* very old datasheets said 0x490c for SDR104, too. They are wrong! */ @@ -562,23 +559,25 @@ static void renesas_sdhi_scc_reset(struct tmio_mmc_host *host, struct renesas_sd }
/* only populated for TMIO_MMC_MIN_RCAR2 */ -static void renesas_sdhi_reset(struct tmio_mmc_host *host) +static void renesas_sdhi_reset(struct tmio_mmc_host *host, bool preserve) { struct renesas_sdhi *priv = host_to_priv(host); int ret; u16 val;
- if (priv->rstc) { - reset_control_reset(priv->rstc); - /* Unknown why but without polling reset status, it will hang */ - read_poll_timeout(reset_control_status, ret, ret == 0, 1, 100, - false, priv->rstc); - /* At least SDHI_VER_GEN2_SDR50 needs manual release of reset */ - sd_ctrl_write16(host, CTL_RESET_SD, 0x0001); - priv->needs_adjust_hs400 = false; - renesas_sdhi_set_clock(host, host->clk_cache); - } else if (priv->scc_ctl) { - renesas_sdhi_scc_reset(host, priv); + if (!preserve) { + if (priv->rstc) { + reset_control_reset(priv->rstc); + /* Unknown why but without polling reset status, it will hang */ + read_poll_timeout(reset_control_status, ret, ret == 0, 1, 100, + false, priv->rstc); + /* At least SDHI_VER_GEN2_SDR50 needs manual release of reset */ + sd_ctrl_write16(host, CTL_RESET_SD, 0x0001); + priv->needs_adjust_hs400 = false; + renesas_sdhi_set_clock(host, host->clk_cache); + } else if (priv->scc_ctl) { + renesas_sdhi_scc_reset(host, priv); + } }
if (sd_ctrl_read16(host, CTL_VERSION) >= SDHI_VER_GEN3_SD) { diff --git a/drivers/mmc/host/tmio_mmc.c b/drivers/mmc/host/tmio_mmc.c index b55a29c53d9c..53a2ad9a24b8 100644 --- a/drivers/mmc/host/tmio_mmc.c +++ b/drivers/mmc/host/tmio_mmc.c @@ -75,7 +75,7 @@ static void tmio_mmc_set_clock(struct tmio_mmc_host *host, tmio_mmc_clk_start(host); }
-static void tmio_mmc_reset(struct tmio_mmc_host *host) +static void tmio_mmc_reset(struct tmio_mmc_host *host, bool preserve) { sd_ctrl_write16(host, CTL_RESET_SDIO, 0x0000); usleep_range(10000, 11000); diff --git a/drivers/mmc/host/tmio_mmc.h b/drivers/mmc/host/tmio_mmc.h index e754bb3f5c32..501613c74406 100644 --- a/drivers/mmc/host/tmio_mmc.h +++ b/drivers/mmc/host/tmio_mmc.h @@ -42,6 +42,7 @@ #define CTL_DMA_ENABLE 0xd8 #define CTL_RESET_SD 0xe0 #define CTL_VERSION 0xe2 +#define CTL_SDIF_MODE 0xe6 /* only known on R-Car 2+ */
/* Definitions for values the CTL_STOP_INTERNAL_ACTION register can take */ #define TMIO_STOP_STP BIT(0) @@ -98,6 +99,9 @@ /* Definitions for values the CTL_DMA_ENABLE register can take */ #define DMA_ENABLE_DMASDRW BIT(1)
+/* Definitions for values the CTL_SDIF_MODE register can take */ +#define SDIF_MODE_HS400 BIT(0) /* only known on R-Car 2+ */ + /* Define some IRQ masks */ /* This is the mask used at reset by the chip */ #define TMIO_MASK_ALL 0x837f031d @@ -181,7 +185,7 @@ struct tmio_mmc_host { int (*multi_io_quirk)(struct mmc_card *card, unsigned int direction, int blk_size); int (*write16_hook)(struct tmio_mmc_host *host, int addr); - void (*reset)(struct tmio_mmc_host *host); + void (*reset)(struct tmio_mmc_host *host, bool preserve); bool (*check_retune)(struct tmio_mmc_host *host, struct mmc_request *mrq); void (*fixup_request)(struct tmio_mmc_host *host, struct mmc_request *mrq); unsigned int (*get_timeout_cycles)(struct tmio_mmc_host *host); diff --git a/drivers/mmc/host/tmio_mmc_core.c b/drivers/mmc/host/tmio_mmc_core.c index a5850d83908b..437048bb8027 100644 --- a/drivers/mmc/host/tmio_mmc_core.c +++ b/drivers/mmc/host/tmio_mmc_core.c @@ -179,8 +179,17 @@ static void tmio_mmc_set_bus_width(struct tmio_mmc_host *host, sd_ctrl_write16(host, CTL_SD_MEM_CARD_OPT, reg); }
-static void tmio_mmc_reset(struct tmio_mmc_host *host) +static void tmio_mmc_reset(struct tmio_mmc_host *host, bool preserve) { + u16 card_opt, clk_ctrl, sdif_mode; + + if (preserve) { + card_opt = sd_ctrl_read16(host, CTL_SD_MEM_CARD_OPT); + clk_ctrl = sd_ctrl_read16(host, CTL_SD_CARD_CLK_CTL); + if (host->pdata->flags & TMIO_MMC_MIN_RCAR2) + sdif_mode = sd_ctrl_read16(host, CTL_SDIF_MODE); + } + /* FIXME - should we set stop clock reg here */ sd_ctrl_write16(host, CTL_RESET_SD, 0x0000); usleep_range(10000, 11000); @@ -190,7 +199,7 @@ static void tmio_mmc_reset(struct tmio_mmc_host *host) tmio_mmc_abort_dma(host);
if (host->reset) - host->reset(host); + host->reset(host, preserve);
sd_ctrl_write32_as_16_and_16(host, CTL_IRQ_MASK, host->sdcard_irq_mask_all); host->sdcard_irq_mask = host->sdcard_irq_mask_all; @@ -206,6 +215,13 @@ static void tmio_mmc_reset(struct tmio_mmc_host *host) sd_ctrl_write16(host, CTL_TRANSACTION_CTL, 0x0001); }
+ if (preserve) { + sd_ctrl_write16(host, CTL_SD_MEM_CARD_OPT, card_opt); + sd_ctrl_write16(host, CTL_SD_CARD_CLK_CTL, clk_ctrl); + if (host->pdata->flags & TMIO_MMC_MIN_RCAR2) + sd_ctrl_write16(host, CTL_SDIF_MODE, sdif_mode); + } + if (host->mmc->card) mmc_retune_needed(host->mmc); } @@ -248,7 +264,7 @@ static void tmio_mmc_reset_work(struct work_struct *work)
spin_unlock_irqrestore(&host->lock, flags);
- tmio_mmc_reset(host); + tmio_mmc_reset(host, true);
/* Ready for new calls */ host->mrq = NULL; @@ -961,7 +977,7 @@ static void tmio_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) tmio_mmc_power_off(host); /* For R-Car Gen2+, we need to reset SDHI specific SCC */ if (host->pdata->flags & TMIO_MMC_MIN_RCAR2) - tmio_mmc_reset(host); + tmio_mmc_reset(host, false);
host->set_clock(host, 0); break; @@ -1189,7 +1205,7 @@ int tmio_mmc_host_probe(struct tmio_mmc_host *_host) _host->sdcard_irq_mask_all = TMIO_MASK_ALL;
_host->set_clock(_host, 0); - tmio_mmc_reset(_host); + tmio_mmc_reset(_host, false);
spin_lock_init(&_host->lock); mutex_init(&_host->ios_lock); @@ -1285,7 +1301,7 @@ int tmio_mmc_host_runtime_resume(struct device *dev) struct tmio_mmc_host *host = dev_get_drvdata(dev);
tmio_mmc_clk_enable(host); - tmio_mmc_reset(host); + tmio_mmc_reset(host, false);
if (host->clk_cache) host->set_clock(host, host->clk_cache);